Forum for Science, Industry and Business

Genetically modified rice in China benefits farmers health

29.04.2005

Farmers growing genetically modified rice in field trials in China report higher crop yields, reduced pesticide use and fewer pesticide-related health problems, according to a study by researchers in China and at Rutgers University and the University of California, Davis. Results of the study will appear in the April 29 issue of the journal Science.

"This paper studies two of the four GM varieties that are now in farm-level preproduction trials, the last step before commercialization" says study co-author Carl Pray, an agriculture, food and resource economics professor at Rutgers Cook College who specializes in the economics of technology change in the agriculture of developing countries. "Farm surveys of randomly selected farm households that are cultivating the insect-resistant GM rice varieties demonstrate that when compared with households cultivating non-GM rice, small and poor farm households benefit from adopting GM rice by both higher crop yields and reduced use of pesticides, which also contributes to the improved health of farmers."

China began doing research on genetically modified agricultural crops in the 1980s. Although it has aggressively commercialized "Bt cotton," genetically modified to produce a natural pesticide against the bollworm, China has not developed any genetically modified food crops for the commercial market.

He and colleagues set out to conduct an economic analysis of data from eight rice pre-commercialization field trials in China. Their goal was to determine whether genetically modified rice was helping farmers reduce pesticide use in the fields, increasing yield and having any identifiable health effects on the farmers growing the genetically modified rice strains.

They examined data from field trials involving two genetically modified rice strains: the Xianyou 63, created to be resistant to rice stem borer and leaf roller through insertion of a Bacillus thuringiensis (Bt) gene, and the Youming 86 variety, which is insect-resistant due to introduction of a resistance gene from the cowpea plant. Both varieties have been in pre-production field trials since 2001.

These field trials in China were designed to identify the effects of the genetically modified crops on farm households before the new crops are commercialized. The field trials of Xianyou 63 are being conducted by farmers in seven villages in five counties and of Youming 86 in one village in Fujian province.

The farmers received no compensation for participating in the two-year study. They grew the rice without help or advice from technicians, making all of their own decisions on whether or not to apply pesticides on both genetically modified insect-resistant rice and non-genetically modified rice. They based their decisions on whether to apply pesticides on observations of the severity of pest infestations, rather than on any prescribed dosages of pesticide.

The 2002 survey included 40 farmers who devoted all or part of their acreage to a genetically modified rice strain and 37 farmers who planted all non-genetically modified rice. In 2003, because more insect-resistant rice seed had been distributed, the survey included 69 farmers who planted all OR part of their fields to genetically modified rice and 32 farmers who grew only conventional rice varieties.

Data from the surveys revealed that the characteristics of the farm households were nearly identical, regardless of what type of rice they were growing. For example, there was no statistical difference between the farms in terms of size, share of rice in the farms cropping pattern, or in the farmers age or education.

Pesticide Use

The main difference between the farm households was in the level of pesticides they used. The study showed that the farmers applied the same types of pesticides, regardless of what type of rice they were growing. However, the farmers growing the genetically modified rice strains applied pesticides less than once per season, while farmers growing conventional rice varieties applied pesticides 3.7 times per season.

Measured on a per hectare (2.471 acres) basis, the quantity and cost of pesticides applied to the conventional rice was 8 to 10 times as high as that applied to the insect-resistant genetically modified rice.

In short, use of the genetically modified rice enabled the farmers to reduce pesticide use by 15 pounds per acre, an 80-percent reduction when compared with pesticide use by farmers using conventional rice varieties.

Rice yields

The survey data also showed that there was a difference in yields between the genetically modified and non-genetically modified rice varieties. Yields of the genetically modified Xianyou 63 variety were 9 percent higher than those of conventional rice varieties. Yields of the genetically modified Youming 86 were not significantly different from those of conventional varieties, however researchers note that there were relatively few observations of this variety because it was grown in only one village by comparatively few farm households.

Pesticide related illnesses

Because there is a high incidence of pesticide-related illness in households of developing countries, including China, the researchers were interested in tracking the health effects of insect-resistant genetically modified rice. They asked farm family members if they experienced any headaches, nausea, skin irritation, digestive discomfort or other health problems during or after spraying pesticides on their farms. If so, the researchers asked them if they had visited a doctor, gone home to recover or taken other actions to deal with the symptoms. If they had, it was recorded as a case of pesticide-induced illness.

The survey indicated that none of the farmers who had completely planted their farms to genetically modified insect-resistant rice varieties reported experiencing adverse health effects from pesticide use in either 2002 or 2003.

Of those farm households that grew plots of the genetically modified rice and plots of conventional rice varieties, 7.7 percent reported pesticide-induced illness incidents in 2002, and 10.9 percent reported such cases in 2003. None of those households reported being affected after working on plots planted to the genetically engineered varieties.

Among the farm households that used conventional rice varieties, 8.3 percent in 2002 and 3.0 percent in 2003 reported adverse health affects related to pesticide use.

Die letzten 5 Focus-News des innovations-reports im Überblick:

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.